It's been about 8 years since I played it, and my memory isn't super strong on that front. But actually, the worst part about that game, which almost made me quit, was a section towards the end of the game which my laptop at the time just could not handle for whatever reason, and so I had to very carefully get through it by pressing keys one at a time, alt tabbing out and back in and seeing where I ended up. I had to do this while avoiding the on screen enemies as well as not jumping off the edge. IIRC it was Snow Mountain?

I haven't actually played LISA the Joyful but I always intended to! If I ever replay LISA and then go on to play Joyful then I don't think I'll subject myself to pain mode or anything lol, I just remember that I wanted to see the true ending!